The invention relates to a constant velocity tripode joint having an outer joint part with an inner aperture and three uniformly circumferentially distributed recesses which widen the inner aperture. Each recess includes two opposed tracks. The tripode joint also has an inner joint part with a center piece having three uniformly circumferentially distributed tripode arms that are arranged radially relative to the center piece and that each extend into one of the recesses. The tripode joint further includes roller assemblies each of which is rotatably supported on one of the tripode arms and that are in rolling contact with the tracks of their respective recesses.
Tripode joints of this type serve to transmit torque between the inner joint part and the outer joint part and are used especially in the drivelines of motor vehicles. When the joint rotates and when the longitudinal axes of the inner joint part and of the outer joint part are articulated relative to one another, the roller assemblies, in their respective recess, periodically move longitudinally to and fro. In tripode joints wherein the roller assemblies are held coaxially on the tripode arms, the roller assemblies carry out periodic angular movements that are superimposed on the longitudinal movements and their angle is twice the size of the angle of articulation between the longitudinal axes. To the extent that the roller assemblies are held angularly movably on the tripode arms, the longitudinal to- and fro- movements take place with the roller axes of the roller assembly extending parallel relative to one another.
During the transmission of torque, the roller assemblies each rest against one of the tracks of the recesses in a coinciding circumferential direction, whereas there necessarily exists a gap between the roller assembly and the other one of the tracks of the respective recess. There exist some restrictive effects because the edges of the second track are alternately contacted by outer annular edges of the roller assemblies. When the tripode joint rotates in a torque-free way, such as is the case when a vehicle changes from operating under load to a pushing operation or when it is operated in a substantially load-free condition, the contact of the roller assemblies changes between the two tracks of each of the recesses. The change in contact is associated with noise generating pulses and the noise adversely affects driving comfort.
It is therefore the object of the present invention to develop a constant velocity tripode joint of the above-mentioned type in such a way that the noise generated by the change in contact of the roller assemblies between the tracks of the recesses during torque-free operation is reduced.